Competition and evolutionary stability of plants in a spatially structured habitat

We modelled the population dynamics of two types of plants with limited dispersal living in a lattice structured habitat. Each site of the square lattice model was either occupied by an individual or vacant. Each individual reproduced to its neighbors. We derived a criterion for the invasion of a rare type into a population composed of a resident type based on a pair-approximation method, in which the dynamics of both average densities and the nearest neighbor correlations were considered. Based on this invasibility criterion, we showed that, when there is a tradeoff between birth and death rates, the evolutionarily stable type is the one that has the highest ratio of birth rate to mortality. If these types are different species, they form segregated spatial patterns in the lattice model in which intraspecific competitive interactions occur more frequently than interspecific interactions. However, stable coexistence is not possible in the lattice model contrary to results from completely mixed population models. This clearly shows that the casual conclusion, based on traditional well mixed population models, that different species can coexist if intraspecific competition is stronger than interspecific competition, does not hold for spatially structured population models.     

企业成长分析

通过建立企业成长分析框架,探讨了企业成长中可能出现的各种情况,并得出如下结论:企业成长的关 键在于通过提高自身经营能力和调整经营方向来扩大市场空间。     

抛物型方程周期问题的高精度精细积分法

对于抛物型方程（δ/δt-δ^2/δx^2)^2u≡δ^2u/δt^2-2δ^3u/δtδx^2 δ^4u/δx^4=0的初始值与周期边值问题，提出了局部截断误差阶为O(Δx^4)的精细时程积分法．由于这种方法是半解析方法,在时间域上可以精确计算．所以本方法不仅精度高，而且还绝对稳定．文末的数值算例进一步表明，精细积分法对大的时间步长和长时间计算均有效．因此是一种很实用的方法．     

上海浦东新区现代物流产业发展战略与规划研究

经过10多年的大规模开发建设,浦东新区经济发展水平有了明显的提高,与此相对应,物流产业也有了很大的发展,但同时也并存着一些问题和难题。有必要对浦东新区发展物流产业的条件和问题进行分析,并确定今后发展的方向和切入点。     

Growth and Inflation Disparities in Corridor V

The paper offers a brief discussion about the role of transport infrastructure in the current growth strategy followed by the European Union. As a corridor is the locus where transport infrastructure and growth should interact more effectively, the central part of the Corridor V is considered as an interesting case study. A growth scenario for eight countries is provided to show that wide growth disparities are to be expected during the next decade. The final part of the paper speculates about inflation differentials that are likely to emerge when growth differentials tend to persist inside a monetary union. As the Euro zone will be enlarged to host fast-growers in Corridor V such as Slovenia (maybe as soon as 2007), Hungary, and the Slovak Republic, growth differentials and the single monetary policy could make it difficult to deliver a common monetary environment.     

研究与开发、金融体制和经济增长

不同金融体制通过影响研究与开发在经济增长中起不同作用。由单一银行提供研究与开发经费的经济 ,有软预算约束 ,由多元银行提供研究与开发经费的经济有硬预算约束。当研究与开发项目的不确定性很高时 ,具有硬预算约束的经济比具有软预算约束的经济更能促进研究与开发 ,能带来更高经济增长率。     

在转变经济增长方式中落实科学发展观

经济发展包含经济增长但不局限于经济增长。经济发展要求树立科学发展观,转变经济增长方式。转变经济增长方式是落实“三个代表“重要思想的必要措施,是全面建设小康社会,实现可持续发展的客观要求。     

Unions and Employment Growth: Evidence from State Economic Recoveries

We test the hypothesis that in an economic recovery, unionization negatively affects job creation. We examine state-level job growth following two recent recessions, those with troughs in November 1982 and March 1991. In the five years following the troughs, we assess whether variations across states in union membership and right-to-work laws affect the rate of job growth. We find evidence that links union influence to slower job growth during an economic recovery, a finding consistent with previous studies reporting that unions negatively affect average employment and employment growth.

Reviewing Implications of Urban Growth Management and Spatial Governance in the Global South

ABSTRACT

Urban containment policies have been applied in the global north as a strategy towards creating compact urban development. In the south the urban growth management discourse have been part of planning practice for the past three decades. There are however several reasons, both structural and political that have contributed to its limited success. The purpose of the research is to review practices of growth management in the south in an attempt to find lessons from the implementation of different mechanisms. The study focuses on the challenges of growth management mechanisms and its associated spatial governance approaches.     

中国式财政分权与地方经济增长目标管理——来自省、市政府工作报告的经验证据

本文将实际经济增长分解为政府直接调控的"经济增长目标"和主要受市场因素影响但同时也受到政府间接干预的"计划外增长"两项,通过多层级政府框架的一般均衡模型模拟分析发现,财政分权在实际经济增长、经济增长目标和计划外增长方面的效应并不同步,而且还呈现地区差异性。在此基础上,系统搜集中国省、市两级政府2000~2016年政府工作报告里的GDP计划增长目标并进行系统GMM估计。实证结果表明:整体而言,财政分权对省、市实际经济增长的影响皆显著为正,但对其两个分解指标存在非对称性影响:从全国范围来看,财政分权对实际经济增长的正向影响主要体现为对经济增长目标的拉动作用,而对计划外增长影响较弱且不甚显著;分地区回归发现,东部地区财政分权对实际经济增长的正向影响更多地体现为对计划外经济增长的驱动,而西部地区则主要是通过影响由政府直接调控的经济增长目标来实现的。机制分析显示,财政分权通过不同程度地推动基建投资、房地产投资以及工业化进程,促进了经济增长目标的实现,进而推动实际经济增长。